234 THE HORSE AND ITS RELATIVES 



noteworthy that when such striping does occur it is 

 of the narrow type characteristic of Gravy's zebra 

 and the undermentioned bontequagga-pony hybrid. 



All the races of the bontequagga will interbreed ; 

 and it is probable that in some instances the hybrids 

 may be fertile, although they are generally as sterile 

 as mules. Recently a hybrid foal between a female 

 of the Matabili E. b. biwchelli and a male of the 

 East African E. b. granti was born in the Royal 

 Dublin Zoological Gardens. The noticeable feature 

 in this foal is that while the le,^s have the com- 

 plete barring of those of granti, the body shows 

 the shadow-stripes of chapmani ; this illustrating 

 the potency of leg-barring. 



The Matabili bontequagga has been crossed by 

 Professor Ewart with a black pony mare from the 

 Isle of Man and also with bay ponies. The resulting 

 progeny (pi. xxi. fig. i) were bay in ground-colour, 

 but more or less fully marked, with narrow and 

 closely approximated dark stripes, quite unlike those 

 of the male parent in width and number, and to a 

 considerable extent also in direction. Probably, 

 as in the instances noted above, they indicate 

 reversion towards an earlier ancestral type. 



Hybrids of this type have been used for draught 

 and riding in countries unsuited to horses, and they 

 are believed to be immune to the attacks of tsetse- 

 fly. Whatever may be their value under such cir- 

 cumstances, it is unlikely that these zebra-hybrids, 



