TELKGONY AND REVERSION, 



89 



evidently sometimes reduced either by two or more blending, 

 or by alternate stripes first forming shadow stripes and then 

 disappearing, the nine to ten vertical body stripes in the 

 common zebra may be equivalent to the eighteen to twenty 

 stripes in the Somali zebra. In the Burchell zebras, when 

 the shadow stripes (Fig. 25j are included, there are often 

 eleven vertical stripes* between the shoulder stripe and the 

 great flank stripe, i. e. the stripe corresponding to one of 



Fig. 30. 



Mountain Zebra and Foal (Amsterdam Zoological Gardens). 



the handles of the gridiron in the common zebra. Hence 

 the only essential difference between the Bui^chell and the 



lighter, until they are almost invisible ; but when within two or three 

 inches of the ventral baud they become nearly as distinct as they are on 

 the sides of the body. 



* In Matopo four vertical stripes reach the ventral band (Fig. 23), 

 while in the Transvaal filly (Fig. 25) three stripes on one side and two 

 on the other reach the ventral band. 



