56 THE HORSE AND ITS RELATIVES 



much the same manner as are those on the coats of 

 young tapirs. A certain amount of support to this 

 theory is afforded by the circumstance that it tends 

 to bring two famiHes of the odd-toed section of 

 the hoofed mammals into Hne with one another in 

 the matter of colouring. 



These hypothetical white markings of the ances- 

 tral members of the horse tribe are presumed to have 

 taken in the first instance the form of simple round 

 spots, which subsequently tended to arrange them- 

 selves in lines and then to coalesce into longitudinal 

 streaks, but finally underwent a rearrangement, so 

 as to produce light transverse bars or stripes on the 

 greater portion of the head and body. On this 

 view, zebras should be regarded as black or brown 

 animals with white or buff stripes, and not, after the 

 ordinary fashion, as white ones with dark stripes ; 

 this idea having been suggested some years previous 

 to the publication of Mr. Pocock's paper by Sir 

 H. H. Johnston. Similarly, there appear to be 

 good grounds for considering that giraffes were 

 originally brown or red animals with vertical white 

 stripes arranged like those of elands and their 

 cousin the bongo antelope of the forests of 

 Equatorial Africa. 



It may be added that dappling occurs only in 

 domesticated horses and occasionally in asses and 

 mules, and that it is very rare in duns. From its 

 absence in the wild Mongolian horse, which may 



