3(1. The ass (Equus Asinus), at once recog nisable by the length of its cars, by the tuft of hair at the end of its tail, and by the black cross upon its shoulders, which is the first appearance of those transverse bands which become numerous in the succeeding species. This animal seems to be indigenous to the desert regions of Central Asia, where vast troops of them still abound in a wild state.
4th. The Zebra (Equus Zebra), a native of the southern regions of Africa, and conspicuous for its symmetry and the alternate transverse stripes of black and white with which its skin is all over marked.
5th. The Quagga (Equus Quaecha), a native of the same regions as the Zebra, from which it principally differs in the colour of its skin and more horse-like appearance. Its hair upon tbe neck and shoulders is brown, marked transversely with white stripes ; its croup is of a greyish-red colour, while the tail and legs are white. The name of this anithal is derived from its peculiar voice, which some what resembles the bark of a dog.
6th, The Onagga, or Dauw (Equus mon (anus), is somewhat less than the ass, and in, its shape resembles the quagga. Its general
colour is a light bay marked with black stripes, that are alternately broader and narrower over the head, neck, and trunk ; the hinder stripes are directed obliquely forward, while the legs and tail remain white.
With respect to their anatomy, it may be observed, that all the above species resemble each other as closely in their internal economy as they do in outward form, and accordingly, in the following pages, we shall confine our selves principally to a description of the horse, as being the typical species of the group, noticing, however, incidentally, such peculiarities of structure as may be worthy of remark in the humbler congeners of their noble prototype. So near, indeed, is the relationship between the different members of the entire genus, that they will breed together . without difficulty, although the progeny of such a union, the mule, is generally incapable of reproduction. Such is well known to be the ca.se between the horse and the ass, as also with the zebra, and doubtless with the genus generally.