To give a clearer idea of the different kinds of dogs, of their propagation in different climates, and of the mixture of their breeds, I subjoin a kind of genealogical tree, in which all the different varieties may easily be distinguished. The shepherd's dog is the stock or body of the tree. This dog, when transported into the rigorous climates of the north, such as to Lapland, becomes ugly and small, but in Russia, Iceland, and Siberia, where the climate is rather less rigorous, and the people more civilized, he is not only preserved, but even brought to greater perfection. These changes are occasioned solely by the influence of those climates, which produces no great alteration in his form, for in each of them he has erect ears, long and thick hair, and a wild look; he barks also less frequently, and in a different manner from those that in more favourable regions have been brought to greater perfection. The Iceland dog is the only one that has not his ears entirely erect, but which bend or fold a little at their extremities; and Iceland is, of all the northern countries, that which has been most anciently inhabited by half-civilized men. The same shepherd's dog, transported into temperate climates, and among people perfectly civilized, as those of England, France, or Germany, loses its savage air, erect ears, its long, thick, and rough hair, and takes the form of the hound, bull-dog, and mastiff. Of the two latter the ears are still partly erect, or only half-pendent; and in their manners and sanguinary dispositions very much resemble the dog, from which they draw their origin. The hound is the most distant of the three; his ears are long and pendent, and the gentleness, docility, and, we may say, the timidity of this dog, are so many proofs of the great degeneration, or, more properly, the great perfection he has acquired by a long state of domesticity, and a careful education bestowed on him by man. The hound, the harrier, and the terrier, are only one race, for it has been remarked that in the same litter there have been harriers, terriers, and hounds, though the female hound had been only covered by one of the three dogs. I have coupled the Bengal harrier with a common harrier, because they differ only by the number of spots upon their coats. I have also coupled the turnspit, or terrier with crooked legs, with the common terrier, because the defects in the legs of this dog only proceed from a disease somewhat like the rickets, with which some individuals have been attacked, and transmitted the effects to their descendants.