Equus Burchellii.

The well known group of which the Horse, the Ass, and the Zebra constitute the leading species, is distinguished from all other quadrupeds by the form of their hoof, which is single and undivided, rounded in front, of considerable thickness, and enveloping the extremity of their only apparent toe. They have in each jaw six powerful cutting teeth, accompanied on either side by the same number of grinders with square crowns flattened at the top: the males have two canines in the upper jaw, and frequently in the lower also; and this structure is sometimes shared by the females of the domesticated races. Between the canines and the molars[178] there is a vacant space, which, our readers scarcely need to be reminded, receives the bit, the small but irresistible instrument by means of which man has for ages exercised the most complete control over the services of these useful animals. Although purely and essentially herbivorous, their anatomy, as well as their habits, separates them most thoroughly from the Ruminants, and approximates them in several respects to the Pachydermatous order, with which, in spite of their many discrepancies, both physical and moral, M. Cuvier has associated them. It is needless to point out the incongruity of this union, and it would be equally so to say more of the general form and external characteristics of a group, the principal species of which are so constantly before our eyes.

It may, however, be observed, that it has been proposed to divide it into two distinct genera, the one containing the Horse alone, and characterized by the flowing tail uniformly covered with long hair, by the absence of a line of darker coloured hairs along the back, and by the presence of callous protuberances on the hind legs as well as on the fore: the other comprehending the Asses and Zebras, and distinguished by the tail having a brush of long hairs at its extremity only, by the presence of the dorsal line, and the absence of the protuberances on the posterior legs. Such a division, resting as it does on striking but not very essential differences, may fairly be admitted for the purpose of separating the genus into sections; but can hardly be regarded as founded on characters of sufficient importance to disunite so well marked and strongly connected, as well as so limited, a group. In the same paper in[179] which this new arrangement was proposed, the beautiful animal which we have now to describe was first specifically distinguished by Mr. Gray from the Common Zebra, with which it had previously been confounded, and characterized by him under the name of the Asinus Burchellii. Still there exists so much ............