4. The small ox of Belon which we have seen, and call by the name of _zebu_, is no more than a variety in the species of the ox. 5. The _bonasus_ of Aristotle is the same animal as the bison (_fig. 138._) of the Latins. 6. The _bison_ of America might originally come from the bison of Europe. 7. The _urus_ or _aurochs_, is the same animal as our common bull, in his wild and natural state. 8. The bison only differs from the aurochs by accidental varieties, and consequently he is, as well as the aurochs, of the same species as the domestic ox; so that, it appears, all the denominations, and all the pretended species of the ancient and modern naturalists may be reduced to three; namely, the ox, the buffalo, and the bubalus. I do not doubt that some of the propositions which I have laid down will appear mere bold assertions, particularly to those who are employed with the nomenclature of animals, or have endeavoured to give a catalogue of them; nevertheless, there is not one of these assertions which I am not able to prove. But before I enter into critical discussions, each of which demand particular propositions, I shall explain the observations and facts which conducted me into this enquiry, and which having satisfied me, may also prove satisfactory to others. Domestic animals in very few respects resemble wild ones; their nature, their size, and their form, are less constant, and more subject to changes, especially in the exterior parts of the body. The influence of climate, so powerful over all Nature, acts with more force upon captive animals, than upon free. Food prepared by the hand of man, oftentimes scantily given and ill-chosen, joined to the inclemency of a foreign sky, in time produces alterations sufficiently deep to become constant, and to be perpetuated from one generation to another. I do not pretend to say, that this general cause of alteration is so powerful as to essentially alter the nature of beings, whose constitution is so fixed as that of animals; but it changes them in certain respects; it disguises and transforms them externally; it takes away from some parts, and gives rise to others; it paints them with various colours, and by its action upon the habit of the body, it has an influence on their dispositions, instincts, and most interior qualities. A single part changed in a composition so perfect as that of an animal body, is sufficient to make the whole sensible of the alteration; and it is for this reason, that our domestic animals differ almost as much in dispositions and instincts as in figure from those who continue at large in their natural state. Of this, the sheep furnishes a striking example; this species, such as it is at present, perishes in a very short time, if man ceases from tending it with care: it is also greatly changed, and very inferior to its original species. But to adhere to our present subject; we see what changes the ox has gone through, from