n] 



THE EXISTING EQUIDAE 



79 



degree in the quagga (whose geographical range seems always 

 to have been south of the Vaal River), the stripes on the 

 hind-quarters breaking up into spots (Fig. 38), which in turn 

 disappear (Fig. 39), whilst by the diffusion of colour from the 

 stripes the upper parts become a bay colour, the stripes only 

 surviving from the head to the middle of the back (Fig. 40). 

 To this question I shall return (p. 437) when I shall describe 

 and figure a new specimen of the quagga (Figs. 131-3). 



FIG. 40. The Daniell Quagga. 



Now it will be admitted that the Equidae, as a whole or 

 in part, are either gradually divesting themselves of stripes 

 or gradually putting them on, unless it be contended that a 

 separate act of creation has taken place in the case of each 

 species or variety. If as a whole they are in process of getting 

 rid of the marking of a many-striped ancestor, it is clear that 

 the Equidae of Asia and Europe have succeeded in doing this 

 to a far greater degree than their brethren in Africa, to which 

 continent the zebras are confined. On the other hand, if the 

 Equidae, either as a whole or only certain species, are gradually 

 assuming stripes (a less likely hypothesis), it is plain that those 



