DOFFER is that part of a carding-machine which takes the cotton from the cylinder when carded. See CARDING.
DOG, Canis, a genus of digitigrade (q.v.) carnivorous (q.v.) qUadrupeds, which, as defined by Linnmus, included all that now form the family eanida? (q.v.), and also hyenas. In the genus as now restricted, wolves and jackals are generally included by naturalists, along with thoSe animals to which alone the name dog is popularly applied, and a distinctive character of principal importance is found in the pupil of the eye, which is always round—contracting circularly, whilst in foxes it assumes the form of a section of a lens when contracted. The present article is limited to dogs in the common acceptation of the term, wolves and jackals being the subjects of separate articles; and only remarks relative to dogs in general will here find a place, many of the particular kinds being sufficiently important to be separately noticed.
At the very outset we encounter one of the most perplexing and difficult questions in natural history, as to the number of species of dog, and the origin of the domestic dog; two questions in appearance, but rather one in reality, and one on which the opinions of the most eminent naturalists are very much divided. According to some, all domestic dogs are to be regarded as of one species; and as in the case of some other valuable domestic animals, that species is not certainly known to exist in a truly wild state, all the wild dogs which must be admitted to belong to the same species being viewed as the offspring of domestic dogs which have returned to a wild state, and in which, however, it is supposed that the original type or characteristics of the species, modified by domestication, have in a great measure reappeared. According to others, there are numerous Species of dog, originally distinct, which have been domesticated by the inhabitants of different countries, but which, however, are very nearly related not only in their physical characters but in their dispositions and in sonic of their principal instincts, and which were capable of intermixing, not perhaps indiscrim inately, but within certain limits, and so is to produce new races. By some who bold the first of opinions, it is further maintained tbat.th,e wolf and•the dog are one w species, and that all domestic dogs are derived from the wolf; whilst others advocate the claims of the jackal to be regarded as their original parent and, type: - By some of those who hold the species to be numerous, it is supposed not improbable that the .blood of wolves and of jackals may he mixed in some of the domestic races with that of the original dogs. It is impossible for us to do more than state these different views, and a few of. the principal arguments by which they are supported,.
It is admitted on all handsi that there is great diversity among, the different kinds of domestic dogs, many distinct races having long existed, which differ net only in sizo and other physical characters, but to a notable extent also. in dispositions and instincts; it is further admitted that there appear to be.no definite limits to the possible. intermix ture of these races with each other. So great is the,diversity of physical characters, that naturalists of the greatest eminence almost acknowledge themselyes incapable of pointing out any that are common to all, dogs, and yet distinguish them all from the different species of wolves and jackals; and in-fact, the recurred tail, not apparently a character of the first importance, is named by Cuvier himself as the.inest certain, and unvarying specific. distinction. . The obliquity of the eyes of wolves is also contrasted with the more forward direction of those of dogs, .which is acconnted for—in favor of the theory of wolfish origin—by the supposition that it results from the constant habit, for many successive generations, of looking forwards to their master, and obeying his voice."—Bell's British Quadrupeds. This,.on the other, side, is treated with ridicule; it is certainly a transition from the region of observation and ascertained fact to that of mere theory and conjecture. In size, dogs differ so widely that one is not as large as the head of another; the difference in form of body, head, or limbs, is almost equally great between the Newfoundland dog or the mastiff and the greyhound. The grada tions, however, from one form or character to another, render it impossible to draw a fixed limit. In some races of dog, the hind-feet as well as.the forefeet have five toes, instead of four, which is more common; but this has not been much insisted on as a ground of specific distinction. Greater value ought perhaps to be attached to the want in some, as the dholes (q.v.) of India, of the second tubercular tooth in the lower jaw; the hairiness of the soles of the feet of some is perhaps also not unimportant; and in favor of the opinion that domestic dogs have originated from an intermixture of several species, it has been urged that the number of teats in the female varies, and that there is sometimes even a difference between the number on one side and on the other, which has never been observed to be the case in wild dogs, and in them the number in the same kind is always uniform. Some of these points, however, have not received the ; investigation necessary to a confident determination of the measure of importance which ought to be assigned to them.