126 
SAVAGE SUDAN 
But before relating that incident, it will be appropriate 
briefly to summarise the racial distinctions of the water- 
buck throughout Africa. Its range extends over the 
whole continent, from the confines of Cape Colony to 
Sahara ; but in all that wide extension it exhibits but two 
types worthy of separate specific rank. These two are 
(i) In the South — Cobus ellypsiprymnus. —Known 
as the “Common waterbuck”—-until East Africa was 
Two Waterbuck Bulls. 
(Sketched io miles north of Renk, March 14th, 1919.) 
discovered! Distinguished by the conspicuous elliptic 
band of pure white encircling an otherwise dark stern—as 
it were, like a target. 
(2) In the North — Cobus defassa , or Sing-sing water- 
buck, in which the white circle is replaced by an entirely 
pale-coloured stern, similar to that in red deer and in 
many of the antelopes—see sketch above. 
No. 1 extends northward but in gradually deteriorat¬ 
ing form till it finally peters out by the Equator; but 
precisely at that geographic symbol the vacated place is 
reoccupied by a new and vigorous form, bigger, and of 
