the combined effects of climate, nourishment, and treatment, in a wild, and in a domestic state. The most general, and most remarkable variety in domestic and even wild oxen, consists in that sort of hunch which some have between the shoulders: this race of oxen are called _bisons_, and it has been hitherto believed, that they were of a different species from the common ox; but as we are assured, that they produce together, and that the hunch diminishes in the first generation, and disappears in the second or third, it is evident, that this hunch is only a variable and accidental character, which does not prevent the bison from belonging to the same species with the common ox. There were formerly in the desart parts of Europe, wild oxen, some without hunches, and others with them; thus the variety seems to be natural, and to proceed from the abundance and more substantial quality of food; for we remarked, when treating of the camels, that when those animals are lean, and badly fed, they have not even the appearance of a hunch. The ox without a hunch was named _vrochs_, and _turochs_, in the German tongue; and the ox with a hunch, in the same language, was termed _visen_. The Romans, who knew neither of these wild oxen before they saw them in Germany, adopted those names; of _vrochs_ they made _vrus_; and of _visen_, _bison_; and they never imagined that the wild ox described by Aristotle, under the name of _bonasus_, could possibly be either of these oxen, whose names they had thus latinised. Another difference between the aurochs and the bison is the length of the hair; the neck, shoulders, and throat of the bison are covered with very long hairs; while the aurochs have all these parts covered with a short hair, resembling that of the rest of the body, the front excepted, which has frizzled hair. But this difference of the hair is still more accidental than that of the hunch, and, like that, depends on the food and climate, as we have already proved in the goats, sheep, dogs, cats, &c. Thus, neither the hunch, nor the difference in the quantity of hair, are specific characters, but merely simple and accidental variations.