At the same time I had three young foxes, two males and a female, which had been taken with snares and kept in separate places. I had one of these fastened with a long light chain, and had an hut built to shelter him. I kept him in this manner several months, and though he seemed pensive and had his eyes constantly fixed on the country, which he could see from his hut, yet he had constantly good health and appetite. A bitch in season was put to him, but as she would not remain near the fox, she was chained in the same place and plenty of food was given them. The fox neither bit nor used her ill, and during the ten days they remained together, there was not the smallest quarrel between them, neither night or day, nor when they fed; he even approached her familiarly, but as soon as he scented his companion, the signs of desire disappeared, he returned in a melancholy manner to his hut, and no intercourse took place. When the ardour of this bitch was gone, another and even a third and fourth were put to him in the same manner; he treated them all with the same gentleness and with the same indifference; to ascertain whether it was natural repugnance, or the state of restraint he was kept in, prevented his coupling, I had a female of his own species brought to him, which he covered more than once the same day, and upon dissecting her a few weeks afterwards we found she was impregnated, and would have produced four young ones. The other male fox was successively presented with several bitches in season; who were shut up with him in a close courtyard, but he discovered neither hatred nor love to them; they had neither combats nor caresses, and he died a few months after either of disgust or melancholy.
These experiments prove at least that the wolf and fox are very different in their natures from the dog; and that their species are so distinct as to prevent their intermixture, at least in our climates; that consequently the dog does not derive his origin from the wolf or fox, and that the nomenclators who look on these two animals as nothing more than wild dogs, or who imagine the dog to be a wolf, or a fox, become tame, and give to all three in common the name of Dog, have deceived themselves by not having sufficiently consulted nature.