122 ANTELOPES 



the White Nile. The two groups differ by the circumstance that while 

 in the former this type of specialised colouring is common to the 

 adults of both sexes, in the latter it is restricted to a few old bucks 

 in each herd. Closer examination will reveal certain other striking 

 differences. In the bontebok, for instance (although not in the 

 blesbok), there is a large white rump-patch, while that part of the tail 

 which overlies this patch is also white externally, the lower portion and 

 the whole of the inferior surface being dark. In the adult bucks of 

 the two Nile species, on the other hand, only the inner sides of the 

 buttocks and the inferior surface of the tail are white. Obviously, there 

 must be some good reason for both the resemblances and the differ- 

 ences. In both instances the white on the ears and rump is probably 

 intended to serve as a guide to the members of the herd in flight. 

 From the fact of the special colouring only occurring in a certain 

 number of old bucks of the Nile group, it would appear that these 

 individuals take the lead when the comparatively small herds are in 

 full flight. On the other hand, in the incomparably larger herds of 

 the bontebok a few such individuals would be altogether lost, and 

 consequently both sexes have donned the special colouring. 



In young bonteboks (and blesboks) the face-blaze is blackish, as 

 in the adults of several other members of the hartebeest group ; and in 

 a full-grown buck of one of these species recently living in the Berlin 

 Zoological Gardens the blaze never turned white. 



The following admirable account of the bontebok is condensed and 

 otherwise slightly modified from one furnished by Mr. F. C. Selous : — 



" The first Dutch settlers at the Cape of Good Hope met with 

 a richly coloured species of antelope in the neighbourhood of Cape 

 Agulhas which they named the bontebok — pied or variegated antelope ; 

 and it was more than lOO years later that the nearly allied species 

 known as the blesbok was first encountered on the high open plains to 

 the south of the Orange river in the present Colesberg division of Cape 

 Colony. These blesboks were, however, at first called bonteboks, and 

 the plains over which they once roamed are known as ' bontebok- 

 flats ' to this day. When the Boers crossed the Orange river in 1836 

 and trekked into the plains of what is now known as the Orange 

 River Colony, they met with immense herds of blesboks, but saw no 

 bonteboks. They, however, confused the two species ; those who had 

 some acquaintance with or knew something about bontebok calling 

 the new species by the old name, while the majority (who had never 

 seen or heard of bonteboks) gave it the name of blesbok — from the 

 broad white blaze down the face. A confusion thus arose between 



