1909.] 



DIFFERENTIATION OF ZEBRAS. 



551 



The Orawshay variety of the Burchell Zebra found in Nyassa- 

 land, so far as colour is concerned, as Prof. Ewart has pointed 

 out, is the bridge between the Burchell and Mountain Zehras, as 

 it has black stripes close together, and small stripes on the croup, 

 resembling the " gridiron " of the Mountain Zebra and recalling 

 the small stripes in some Grevy Zebras. 



Text-fig. 144. 



E. hurchelli (Chapman's variety' 



It is now universally held that in the Grevy Zebra we have 

 the oldest type of coloration of the Zebra family, though I have 

 argued elsewhere against the doctrine formerly held that in its 

 skin we have the primaeval livery of the ancestor of all the 

 Equidse. In coloration at least the other two species are more 

 recent than the Grevy. 



I here figure ten skins, two of Grevy's Zebra, and eight of 

 Grant's variety of E. hurchelli. Text-figs. 146 & 147 show the 



