his species, although the whole of these breeds must have proceeded virtually from him. Nature, notwithstanding, never fails to resume her rights, when left at liberty to act. Wheat, if sown in uncultivated land, degenerates the first year; if that is likewise sown it will be more degenerated in the second generation, and if continued for a succession of ages the original plant of the wheat would appear; and, by an experiment of this kind, it might be discovered how much time Nature requires to reinstate herself and destroy the effect of art, which restrained her. This experiment might easily be made on corn and plants, but it would be in vain to attempt it on animals, because they would not only be difficult to couple and unite but even to manage, and to surmount that invincible repugnance they have to every thing which is contrary to their dispositions or habits. We need not, therefore, expect to find out, by this method, which is the primitive race of dogs, or any other animals, which are subject to permanent varieties. But in default of the knowledge of these facts, which cannot be acquired, we may assimilate particular indications, and from those draw probable conjectures. Those domestic dogs which were abandoned in the deserts of America, and have lived wild for 150 or 200 years, though then changed from their original breed, must notwithstanding, in this long space of time, have approached, at least in part, to their primitive form. Travellers say that they resemble our greyhounds; and they say the same of the wild dogs at Congo, which like those in America, assemble in packs to make war with lions, tigers, &c. But others, without comparing the wild dogs of St. Domingo to greyhounds, only say that they have long flat heads, thin muzzles, a ferocious air, and thin meagre bodies; that they are exceedingly swift in the chace, hunt in perfection, and are easily taken and tamed when young; thus these wild dogs are extremely thin and light; and as the common greyhound differs but little from the mastiff, or what we call the shepherd's dog, it is not improbable that these wild dogs are rather of those species than real greyhounds; because on the other hand more ancient travellers have said that the dogs of Canada have ears erect like foxes, and resemble our middle-sized shepherd-dogs; that those of the Antille Isles had very long heads and ears, and had very much the appearance of foxes; that the Indians of Peru had only two kinds, a large and a small one, which they called Alco; that those of the isthmus of America, were very ugly, and that their hair was rough and coarse, which likewise implies they had ears erect. We cannot, therefore, have any doubt that the original dogs of America, before they had any communication with those of Europe, were all of the same race, and that they approached nearest to those dogs which have thin muzzles, erect ears, and coarse hair, like the shepherd's dogs; and what leads me further to believe