comparative enumeration of the animals of the old continent with those of the new. It is generally known, that upon horses being first transported into America they struck the natives with surprise and terror; and that this animal has thriven and multiplied so fast, as to have become almost as numerous there now as it is in Europe. It is the same also with the ass, which has thriven equally in these warm climates, and from which mules have been produced, that are more serviceable than the lamas for carrying heavy loads over the mountainous parts of Chili and Peru. The Zebra is also an animal of the old continent, and which, perhaps, has never been even seen in the new; it seems to require a particular climate, and is found only in that part of Africa which lies between the Equator and the Cape of Good Hope. Oxen were unknown in the islands and on the continent of South America. Soon after the discovery of these countries, the Spaniards transported bulls and cows to them from Europe. In 1550 oxen were employed, for the first time, in tilling the ground in the valley of Cusco. On the continent these animals multiplied prodigiously, as well as in the islands of St. Domingo, Cuba, Barlovento, &c. and in many places they even became wild. The species of horned cattle found at Mexico, Louisiana, &c. which is called the _wild ox_ or Bison, is not produced from the European oxen. The bison existed in America before our race was carried thither; and from the latter he is so different as to authorize the opinion of his being a different species. He has a rise between his shoulders, his hair is softer than wool, is longer before than behind, is curled upon the neck and along the spine of the back; he is of a brown colour, and faintly marked with some whitish spots; he has also short legs, which, like the head and neck, are covered with long hair; and the male has a long tail with a tuft of hair at the end, like that of the lion. These differences seem to be sufficient grounds for considering the ox and bison of different species, yet I will not pretend to determine they are so, because the only characteristic which identifies animals to be of the same species, is their propagating and producing similar individuals, and which fact has never been determined between the bison and the oxen of Europe. M. de la Nux, a member of the royal council of the isle of Bourbon, has favoured me with a letter, in which he says, the hunched-back ox of that island propagates with the common horned cattle; and of great advantage would it be, if persons who live in remote countries would follow the example of this gentleman, in making experimental observations upon animals. Nothing could be more easy than for the inhabitants of Louisiana, to try if the American bison would copulate with the European cow. It is probable they would produce together, and in that case it would be ascertained that the European ox, the hunched-backed species of