WATERBUCKS AND REEDBUCKS 
515 
in the neighborhood of water, they sought it merely to drink. 
They were not very wary. They were grazers, like the rest 
of this genus. Like the common kob they went in big 
bands, each composed of ewes and young rams with one or, 
rarely, two or three old rams; and the old rams were also 
found singly, and occasionally the young rams were in small 
parties by themselves. The old rams were strikingly con¬ 
spicuous, with their deep rich brown, almost black, coats, 
and the sharply contrasted black and white markings on 
their faces. Whether this dark coat is a permanent mark 
of advanced age, or whether the old rams only assume it 
seasonally, we do not know; some of the rams with horns 
as fully developed as those of any we saw were not in this 
adult pelage. It is certainly partly a matter of age and 
partly a matter of individual peculiarity. The young rams 
and ewes were a reddish-yellow, like the ewes of the white- 
withered lechwi. 
Vaughn’s kob, which we found in the dry, thorn-studded 
flats beside the Bahr el Ghazal, is apparently only a color 
phase of the white-eared kob. Its habits were precisely the 
same. Watching a ram that stood almost concealed by tall 
grass, we were struck by the way in which its presence was 
betrayed by the incessant wagging of the ears, to drive 
away the biting flies. The ram stood otherwise motionless; 
and when we were too far off for its partly screened and 
dimly seen shape and color either to conceal or reveal it, 
the motion of its ears attracted attention. 
The most marked character in this long-known race is 
the white ear which in old adult males is wholly white with 
no trace of a darker tip. In immature specimens and in the 
females the ears are ochraceous or buffy with dark-brown 
tips. Another striking characteristic of this race is the dark- 
