131 MAMMALIA. 



A Horse's ag'e is known by his incisors. Tlie muiQie teeth bpp;m to appear about fifteen days after birth ; and 

 at two years and a half the miiUlle ones are reiilaced ; at three and a half the two next follow ; and at four ami a 

 half, tlie outermost or corner teeth. All these teeth, with orij^inally-indented crowns, lose by decrees this character 

 by detrition. At seven and a half or eii^lit years, the depressions are completely ellaced, and the Horse is no 

 lon2:er marked. 



The inferior canines appear at three years and a half, the superior at four years ; they remain pointed until t]'_e 

 sixth, and at ten bctcin to peel away. 



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

 and colour. The principal I'aces even exhibit sensible iliflerences in the form of the head, and in their proportions, 

 each bein^ specially adapted for some particular mode of employment. 



The most beautiful and swift are the Arabs, which have contributed to po-fect the S|janisb Ijreed, and ^vith the 

 latter to form the English : the stoutest and stronc:est are from the coasts nf the North ^fea ; and the must dnni- 

 nutive from the north of Sweden and Corsica. Wild Horses have a ]arg;e head, frizzled hair, and angraceful pro- 

 portions. [If the fi;;ure of Pallas be correct, of the AVild Horse of northern Asia, it is doubtful, from the len<!;th 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 Equusnow extinct is represented on the celebrated 

 mosaic of Palestrina. Bones of this t,^enas are not uncunirnon in the older tertiary ^.trata, and have even been found 

 in those of South America. 



The Hzeg-ffuetai {Erjiiii.-; h>'iiiioniis, Tailas). — 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 mime and [broad] 

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



The Ass (E. asinus, 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. L^O""!^ 0^ t^^6 young have 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 hro/i, 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 

 white in a regular manner. 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. quaccfia, Gm.), resembles the Horse move thnn the Zebra, but inhabits the same country as the 

 latter. Its coat is brown on the neck and shoulders, transversely striped w ith whitish ; the cru})per reddish-grey, 

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



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

 with the handsome fornj 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 MAALMALIANS,— 



RUJIIXANTIA,— 



Is, perhaps, tlie most natural and tho Ijest determined (if the wliolc chiss, feir all the speeies 

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

 present some inconsiderable cxce])tions to the general characters of the otou]). 



The first of these characters is that of having,' no incisors in tlie up|)er jaw, -Hhile the 

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

 shown]. They are replaced above by a callmis pad. Between the ineisurs and the molars 

 is a «ide space, \ilicrc, in some genera, there arc one or two canines.* The nndars, almost 

 alwa^s six in nmrdicr above and below, have their crowns marked with two double crescents 

 the convexity of v\liich is turned inwards in the upper, and outwards in the lower jaw. 



Tlie four feet are each terminated by two toes, and by two hoofs, which itreseut a flat sur- 

 face to each other, appearing as though a single hoof had been cleft: hence the names that 

 have been ap|ibed to these animals, of cloven-footed, bifurcated, &:c. 



Behind the hoof there are always two small spurs, ivhieh are vcsti'i-es of lateral toes. The 



