131 MAMMALIA. 



A Horse's age is known by his incisors. Tlie muicne teeth begin to appear about fifteen days after birth ; and 

 at two years and a half the middle ones are replaced ; at three and a half the two next follow ; and at four and a 

 half, the outermost or corner teeth. All these teeth, with originally-indented crowns, lose by degrees this character 

 by detrition. At seven and a half or eight years, the depressions are completely eftaced, and the Horse is no 

 longer marked. 



The inferior canines appear at three years and a half, the superior at four years ; they remain pointed until the 

 sixth, and at ten begin to peel away. 



The life of a Horse seldom extends beyond thirty years. Every one knows how much this animal varies in size 

 and colour. Tlie principal races even exhibit sensible differences in the form of the head, and in their proportions, 

 each being specially adapted for some particular mode of employment. 



The most beautif\d and swift are the Arabs, which have contributed to perfect the Spanish breed, and with the 

 latter to form the English : the stoutest and strongest are from the coasts of the North Sea ; and the most dimi- 

 nutive from the north of Sweden and Corsica. Wild Horses have a large head, frizzled hair, and ungraceful pro- 

 portions. [If the figure of Pallas be correct, of the Wild Horse of northern Asia, it is doubtful, from the length of 

 the ears and some other characters, whether a distinct species intermediate to the true Horse and the fol- 

 lowing be not represented. M. Serres suspects that a species of Equus now extinct is represented on the celebrated 

 mosaic of Palestrina. Bones of this genus are not uncommon in the older tertiary strata, and have even been found 

 in those of South America. 



The Uzegguetai (Equus hcmiomis, Pallas). — A distinct species, intermediate in its proportions to the Horse and 

 Ass, which lives in troops in the sandy deserts of Central Asia. Colour isabelle, with black mane and [broad] 

 dorsal line ; a terminal black tuft to the tail. This was probably the Wild Mule of the ancients. 



The Ass (jB. asiniis, Lin.). — Known by its long ears, the tuft at the end of its tail, and the black line crossing the 

 dorsal one over its shoulders, which is the first indication of the transverse stripes that occur in the following 

 species. [Some of the young liave obscure cross-bands on the legs.] Originally from the vast deserts of the 

 interior of Asia, the Ass is still found there free and unreclaimed, in numerous troops, which migrate north and 

 south according to the season : hence it does not thrive in countries too much to the north. Its patience, sobriety, 

 hardy constitution, and the services which it renders to the poor, are well known to every one. The harshness of 

 its voice, or bray, is occasioned by two small peculiar cavities situate at the bottom of the larynx. 



The Zebra (E. zebra, Lin.). — Nearly the form of the Ass, and everywhere transversely striped with black and 

 \\hite in a regular maimer. It is indigenous to the whole south of Africa. We have known a female Zebra 

 produce successively with the Horse and the Ass. 



The Couagga (E. quaccha, Gm.), resembles the Horse more than the Zebra, but inhabits the same country as the 

 latter. Its coat is brown on the neck and shoulders, transversely striped with whitish ; the crupper reddish-grey, 

 and tail and legs whitish. Its name expresses the sound of its voice, which is not unlike the bark of a Dog. 



The Onagga or Dauw (E. monfaiim, Burchell). — Another African species, inferior [?] in size to the Ass, but 

 with the handsome form of the Couagga, and of an isabelle colour, striped with alternately broader and more 

 narrow black markings on the head, neck, and body. The hinder stripes are disposed obliquely forward, and the 

 legs and tail are white. 



THE EIGHTH ORDER OF MAMMALIANS,— 



RUMINANTIA,— 



Is, perhaps, the most natural and the best determine<l of the whole class, for all the species 

 which compose it ap])ear to have been constructed on the same model, and the Camels alone 

 present some inconsidei'able exceptions to the general characters of the group. 



The first of these characters is that of having no incisors in the upper jaw, while the 

 inferior has always eight, [the two outermost of which represent canines, as can be easily 

 shown]. They are replaced above by a callous pad. Between the incisors and the molars 

 is a wide space, where, in some genera, there are one or two canines.* The molars, almost 

 always six in number above and below, have their crowns marked with two double crescents, 

 the convexity of which is turned inwards in the upper, and outwards in the lower jaw. 



The fom' feet are each terminated by two toes, and by two hoofs, which ])resent a flat sur- 

 face to each other, a])pearing as though a single hoof had been cleft ; hence the names that 

 have been applied to these animals, of cloven-footed, bifurcated, &c. 



Behind the hoof there are always two small spurs, which are vestiges of lateral toes. The 



* Thnugli acfiuaiiued with sll the sul.divisioDS of «M>«iM</w(r'/, we in the Camels, wherein the inferior eanine lias been rccogmiiH as 

 have never seen more than one canine in any animal « hatcver ; and sueh, there ate never more than sij lower ineiaurs —Ed. 



