Wild animals not being immediately subject to the empire of man, are not liable to such great alterations as the domestic kinds. Their nature seems to vary according to different climates, though they are no where degraded. If they were at liberty to chuse their climate and food these alterations would be still less; but as they have at all times been hunted and exiled by man, or even by those quadrupeds which have greater strength, and are more ferocious, the greatest part of them have been obliged to quit their native country, and to live in climates less favourable to their constitutions. Those which had sufficient flexibility of nature to accommodate themselves to their new situation have dispersed to great distances, whereas others have no resource but to confine themselves within the neighbouring desarts of their native country. There is no species of animal, except man, universally spread over the face of the terrestrial globe. Some, and indeed great numbers, are confined to the southern parts of the Old Continent, and others to the southern parts of the new; while others, though fewer in number, are confined to the cold regions of the north; and, instead of extending themselves towards the south, they have passed from one continent to the other by roads which have hitherto remained unknown to us. There are other species which inhabit particular mountains or valleys, and the alterations of their nature are so much the less apparent the more they are confined to a small space. Climate and food having little influence on wild animals, and the empire of man still less, their principal varieties proceed from another cause. They are relative to the combination of their number in individuals, as well in those which produce as in those which are produced. In those species, like that of the roe-buck, where the male attaches himself to one female, and never changes, the young ones demonstrate the fidelity of their parents by their entire resemblance to them. In those species, on the contrary, where the females often change the male, as in the stag, for instance, there are a number of varieties; and as there is not in nature a single individual which perfectly resembles another, the number of varieties in animals is in proportion to the greater or less frequency of their produce. In species where the female produces five or six young ones, three or four times a year, the number of varieties must necessarily be greater than in those where the produce is annual, and a single one. The inferior species, therefore, which produce oftener, and in greater numbers than the larger, are subject to more varieties. Size of body, which seems only to be a relative quality, nevertheless possesses positive attributes in the laws of Nature. The large species is as fixed as the small is changeable. We shall be convinced of this fact by enumerating the varieties which take place in the large and small animals.